What are the common failure modes of cross cylindrical roller slewing rings?

What is cross cylindrical roller slewing ring

The cross cylindrical roller slewing ring is composed of two seats, the internal cylindrical rollers are arranged in a cross and are separated and positioned by the isolation block, and the unique structure of the roller in contact with the raceway line makes it able to bear strong axial force, radial force and overturning moment at the same time, with the advantages of high load bearing and high precision; It can realize the stable connection and flexible rotation of relatively rotary moving parts, and is widely used in hoisting machinery, construction machinery, port machinery and industrial robots and other equipment with high requirements for bearing capacity and rotation accuracy, providing a strong guarantee for the stable and reliable operation and efficient work of the equipment.

Features of cross cylindrical roller slewing rings

High load-bearing capacity: The cylindrical roller structure with cross arrangement is adopted, and the rollers are in linear contact with the raceway, which can withstand greater axial force, radial force and overturning moment than the point-contact structure, which can meet the needs of heavy equipment and high-load conditions.

High precision: the precise arrangement of the rollers and the positioning of the isolation block make the slewing ring maintain a high rotation accuracy during operation, effectively reduce the shaking and deviation during operation, and can meet some equipment with high requirements for motion accuracy, such as precision machine tools, radar antenna bases, etc.

Compact structure: The structural design of this slewing ring is more compact, occupies less space, and has more advantages in the space layout of the equipment, which is conducive to the miniaturization and lightweight design of the equipment, especially suitable for occasions with limited space but high bearing capacity.

Easy installation: its structural form makes the installation process relatively simple, generally only need to connect the two seat rings with the fixed parts and rotating parts of the equipment respectively through bolts, which can effectively shorten the assembly time of the equipment and improve the production efficiency.

High rigidity: Due to the reasonable arrangement of the rollers and the design of the seat ring, the whole has high rigidity, and the deformation is small when bearing the load, which can ensure the stability of the equipment during operation and prolong the service life of the equipment.

Good interchangeability: The standardized design and manufacture make the cross cylindrical roller slewing ring have good interchangeability, when a component is damaged, it is easy to replace the corresponding part, reducing the maintenance cost and downtime of the equipment.

Wear resistance: The selection of high-quality materials and advanced heat treatment technology makes the roller and raceway surface have high hardness and wear resistance, which can maintain good performance in long-term operation and reduce the impact of wear.

Strong adaptability: It can adapt to different working environments and working conditions, whether it is in high temperature, low temperature, humid or dusty and other harsh environments, as long as appropriate protective measures are taken, it can work reliably and has strong environmental adaptability.

What are the common failure modes of cross cylindrical roller slewing rings?

The common failure modes of cross cylindrical roller slewing rings are as follows:

Wear and tear

Raceway wear: After long-term use, the raceway surface will be worn due to the repeated rolling of the rolling elements, resulting in an increase in the roughness of the raceway surface and a decrease in dimensional accuracy. This will reduce the running accuracy of the slewing ring, produce vibration and noise, and in serious cases, may lead to the increase of the gap between the rolling element and the raceway, and affect the normal operation of the equipment.

Roller wear: When rollers roll within the raceway, their surfaces also wear out. After the roller is worn, it will affect the accuracy of its fit with the raceway, resulting in the decrease of the bearing capacity of the slewing ring, and may also cause the increase of slewing resistance.

Fatigue flaking

Raceway fatigue spalling: Under the action of alternating load, fatigue cracks will gradually appear on the raceway surface, and with the expansion of cracks, it will eventually lead to the metal material spalling on the raceway surface. Fatigue spalling can damage the surface integrity of the raceway, worsen the contact between the rolling element and the raceway, produce shock and vibration, and accelerate the damage to the slewing ring.

Roller fatigue spalling: Rollers can also peel off the surface due to fatigue. Fatigue spalling of rollers not only affects the load-bearing capacity of the slewing ring, but can also cause the rollers to break, which in turn damages the entire slewing ring.

Cracks and fractures

Raceway cracks and fractures: Raceways may crack or even break due to improper installation, overload, shock loads, etc. Raceway cracks can reduce the strength and stiffness of the slewing ring, and once the crack spreads to a certain extent, the raceway will break, resulting in the failure of the slewing ring.

Cage Cracks and Fractures: The function of the cage is to guide and isolate the rolling elements, and cracks or fractures may occur if the cage is subjected to excessive external forces, manufacturing defects, or long-term fatigue. Cracks or fractures in the cage can cause the movement of the rolling elements to lose control and collide with each other, which can seriously damage the slewing ring.

Roller Cracks and Fractures: Cracks or fractures can occur when rollers are subjected to excessive loads or shocks. The crack or fracture of the roller will directly affect the bearing capacity and running stability of the slewing ring, which is a more serious failure mode.

Corrosion: If the slewing ring is in a humid, corrosive environment, or if it is poorly lubricated, its surface is prone to corrosion. Corrosion will rust and peel off the surface of the raceway and rolling elements, reduce the accuracy and bearing capacity of the slewing ring, and also accelerate the occurrence of failures such as wear and fatigue.

Lubrication failure: Lubrication is essential for the proper functioning of cross cylindrical roller slewing rings. Lubrication failure can occur if the amount of lubricating oil is insufficient, the oil quality deteriorates, the lubrication method is improperly lubricated, or the lubricating oil leaks due to poor sealing. Lubrication failure will increase the friction between the rolling elements and the raceway, generate a lot of heat, accelerate wear and fatigue, and in severe cases, lead to slewing ring jamming.

Cross cylindrical roller slewing ring supplier

As a well-known supplier of slewing bearings with 30 years’ experience, LTZC bearings is committed to providing slewing bearings with high quality and low price. The specific price needs to be comprehensively evaluated according to the size, load, material and accuracy requirements of the bearings. Please contact us if necessary.